Pivot connection for the blades of scissors or shears



April 17, 1956 E. SEJMAN ET AL 2,741,843

PIVOT CONNECTION FOR THE BLADES OF SCISSORS OR SHEARS 2 Sheets-Sheet 1Filed NOV. 1, 1952 INVENTORS. EDMUND L. SELIMAN AND L E H.115 LURENZEIfZ ZM'I' I I L AT TURNEY April 17, 1956 L. SEJMAN ET AL PIVOT CONNECTIONFOR THE BLADES OF SCISSORS OR SHEARS 2 Sheets-Sheet 2 Filed Nov. 1, 1952IN VEN TORS. EDMUND L. .SE LIMAN AND ATTORNEY LEIULS LDRENZE] UnitedStates Patent PIVOT CONNECTION FOR THE BLADES 0F SCISSGRS 0R SHEARSEdmund L. Sejman, Devon, and Louis Lorenzo, Bridgeport, Comm, assignorsto The Acme Shear Company, Bridgeport, Couu., a corporation ofConnecticut Application November 1, 1952, Serial No. 318,259

' 4 Claims. 01. 30-266) The present invention relates to a pivotconnection for the blades of scissors or shears, and has for an objectto provide a pivot connection by means of which the tension of theblades, with respect to each other, may be readily adjusted as desired,and following such adjustment, the repeated pivotal movement of theblades will not change the adjustment.

A further object is to provide such pivotal connection in which theadjustment may be made by the simple operation of turning a nut partrelatively to an externally threaded pivot part, such operation beingconveniently carried out by the user of the scissors with the use of acoin, such as a dime, for engaging a slot in the nut part and impartingturning adjustment movement thereto.

A further object is to provide a pivot connection employing relativelysimple and inexpensive parts, and which may be assembled withoutsubstantial alteration in the normal structure of the scissors or shearblades.

With the above and other objects in view, embodiments of the inventionare shown in the accompanying drawings, and these embodiments will behereinafter more fully described with reference thereto, and theinvention will be finally pointed out in the claims.

In the drawings:

Fig. 1 is a side View of a pair of shears embodying the invention;

Fig. 2 is an edge view thereof;

Fig. 3 is a perspective view, on an enlarged scale, showing the severalparts of the pivot connection in separated relation.

Fig. 4 is a transverse sectional view, on a further eularged scale,taken along the line 44 of Fig. l

Fig. 5 is a side elevation of a modified form of shears, namely, pinkingshears, embodying a modified form of the inveniton;

Fig. 6 is an edge view thereof;

Fig. 7 is a perspective view, on an enlarged scale, of the parts of thepivot connection as employed in the modified form of the inventionillustrated in Figs. 5 and 6, shown in separated relation; and

Fig. 8 is a transverse sectional view, on a further enlarged scale,taken along the line 8-8 of Fig. 5.

Similar reference characters indicate corresponding parts throughout theseveral figures of the drawings.

Referring to the drawings, and more particularly to Figs. 14 thereof,the shears illustrated therein comprise a thumb blade member 10 and afinger blade member 11, these being of substantially conventional formhaving thumb and finger engaging loops at one end of the respectiveblade portions. The finger blade 11 is provided with a cylindrical hole12, and the thumb blade 10 is provided with a cylindrical hole 13 and acountersunk recess 14 of circular form.

A pivot element 15 comprises a head 16, a knurled portion 17 adjacentthe head, a smooth cylindrical shank portion 18, and an externallythreaded end portion 19, the latter having a diametrically disposed slot20. This pivot element is fixed to the blade 11 by driving it into the2,741,843 Patented Apr. 17, 1956 hole 12 with a press fit, obtained bymeans of the knurled portion 17, which tends during the drivingoperation to cut into the metal of the blade and thereby firmly fix thepivot element against turning. The shank portion 18 of the pivot elementengages the hole 13 of the blade 10 with a relatively loose fit so as topermit of the normal tilting movement of one blade relatively to theother as the ing surface upon which the blade may pivot.

cutting edges of the blades slide over each other as the blades areopened and closed.

Within the countersunk recess 14 there is engaged a spider washer 21having a diametrically disposed bar 22 across its pivot elementreceiving opening 23, the opening being of such diameter as to beengaged by the threaded portion 19 with the bar 22 disposed in the slot20 of the pivot element, so that the spider washer is locked by thepivot element against relative turning. The fixing of the pivot elementto the blade 11 thus fixes the spider Washer against relative turningwith respect to the blade 11.

The spider washer seats in the base of the countersurdt recess 14 and anut 24 is screwed upon the threaded end 19 of the pivot element andbears upon the upper side of the spider washer, tightening down of thenut thus increasing the tension in the blades and loosening of the nutdecreas ing the tension. A slot 25 is provided in the upper end of thenut and has a concave bottom surface for convenient engagement by theedge of a coin for the purpose of adjusting the nut.

Pivotal movement of the blade 10 about the shank of the pivot elementwill not tend to turn the nut 24 as the spider washer is fixed againstrotation with respect to the pivot element, and thereby provides a fixedthrust bear- As the blade is normally under tension, it exerts axialpressure upon the spider washer and the nut, and thus producesfrictional resistance between the threads of the nut and the pivotelement against turning. In the cutting of thick and thinmaterials, itis desirable to change the blade tension, and this can be quickly andeasily accomplished simply by engaging a coin in the slot of the nut andturning it in the desired direction to increase or decrease the bladetension.

In Figs. 5-8 there is illustrated a modified form of the invention,which is shown as emboded in pinking shears wherein the blades areconstrained against relative tilting movement at the pivot, but have aslight relative movement axially of the pivot during the cutting action.The pinking shears comprise a thumb blade member 27 and a finger blademember 28, these being of substantially conventional form having thumband finger engaging loops at one end cf the respective blade portions,and the blades having interengaging pinking teeth 29 and 30.

Upon the opposed inner sides of the blades there are respectivelyprovided circular bearing bosses 31 and 32, the blade 27 being providedwith a cylindrical hole 33 having its axis centrally of and normal tothe flat bearing surface of the boss 31 and opening at its outer endinto a countersunk circular recess 34. Similarly, the blade 28 isprovided with a cylindrical hole 35 coaxial with and of correspondingdiameter to the hole 33 and opening at its outer end into a countersunkrecess 36 of hexagonal form, which is adapted to non-rotatively receivethe hexagonal head of the pivot element, as will presently more fullyappear.

A circular wear washer 37, having a circular hole 38 substantiallycorresponding in diameter to the holes 33 and 35, is interposed betweenthe bearing bosses 31 and 32, and a tubular cylindrical bearing bushing3? is engaged in the holes 33 and 35 and through the hole 33 of thewasher, the fit of this bearing bushing being such as to allow relativeturning movement of the blades thereon while constraining the bladesagainst any substantial tilting action.

.A pivot element .392: .comprises .a hexagonal .head 40, and acylindrical shank portion 41 having an externally threaded end portion42, the latter having a diametrically disposed'slot 43. This: pivotelement has'its shank engaged through the bearing bushing 39 with itshexagonal head 4% seated inthe recess 36,:the hexagonal form of therecess holding the pivot element against irelative turning movement.Withrespect to :the blade 28.

Within the countersunk recess 34 there 'is engaged a spider washer 44having a diametrically disposed bar 45 disposed in the slot 43 of thepivot element, so that the spider washer is locked by the pivot elementagainst relative turning. As the pivot element is held aga'instturning.with respect to the blade 28 throughthe engagement of the hexagonalhead in the hexagonal recess 3'6, the spider washer is thus fixedagainst relative turning with respect to the blade 23. The spider washerseats in the base of the countersunk recess 34 anda nut 46 is screwedupon the threaded end 42 of the pivotelement and bears upon the upperside of a cupped spring washer 47 interposed between the nut and thespider washer 44, so that the spring washer is tensioned and thustension is set up between the blade members, tightening down of the nutincreasing the tension in the blades and loosening of the nut decreasingthe tension. A slot 43 is provided in the upper end of the nut and has aconcave bottom surface for engagement by the edge of a coin for thepurpose of adjusting the nut.

As in the first embodiment, pivotal movement of the blade 27 about thebearing bushing 39 will-not'tend to turn the nut 46 or the spring washer47, as the spider washer 44 is fixed against rotation with respect tothe pivot element which, in turn, is fixed against rotation with respectto the blade member 28.

l have illustrated and described preferred and satisfactory embodimentsof the invention, but it will be understood that changes may be madetherein within the spirit and scope thereof, as defined in the appendedclaims.

What is claimed is:

1. A pivot connection for the blades of scissors or shears, comprisingfirst and second blade members, each having a hole therethrough incoaxial relation one to the other, a pivot element disposed in saidcoaxial holes, means fixing said pivot element against relative turningwith respect to said first blade member, said second blade memher beingfree to turn about said pivot element and said pivot element having anexternal thread and being disposed partially within said hole of saidsecond blade member and projecting outwardly therefrom, said pivotelement having a diametrically disposed longitudinally extending slot, a

spider washer having a hole loosely engaged about the external thread ofsaid pivot element for free .axial movement thereon and a bar extendingdiametrically across said hole and engaged in said slot to' fix saidspider washer against relative turning movement with respect to saidpivot element, and a nut engaged upon said pivot element at the outerside of said spider washer, the inner side of said washer being inbearing relation with said second blade member.

2. A pivot connection for the blades of scissors or shears, comprisingfirst and second blade members, each having a hole therethrough incoaxial relation one to the other, a pivot element disposed in saidcoaxial holes having a knurled portion fixedly engaged in said hole ofsaid first blade member, said second blade member being free to turnabout said pivot element and said pivot element having an externalthread and being disposed partially within said hole of said secondblade member and projecting outwardly therefrom, said pivot elementhaving a diametrically .disposed longitudinally extending slot, a spiderwasher having a hole loosely engaged about the external thread of saidpivot element for free axial movement thereon and a bar extendingdiametrically across said hole and engaged in said slot to fix saidspider washer against relative turning movement with respect to saidpivot element, and a nut engaged upon the pivotelement at the outer sideof said spider washer, the inner side of said washer being inbearingrelation with said second blade member.

3. A pivot connection for the blades of scissors or shears, comprisingfirst and second blade members, each having a hole therethrough incoaxial relation one to the other, a cylindrical tubular bearing bushingengaged in said coaxial holes, apivot element disposed in said bushing,means fixing said pivot element against relative turning with respect tosaid first blade member, said second blade member being free to turnabout said pivot element and said pivot element having an-externa'lthread and being disposed partially within said hole of said secondblade member and projecting outwardly therefrom, said pivot elementhaving a diametrically disposed longitudinally extending slot, a spiderWasherhaving a hole loosely engaged about the external thread of saidpivot element for free axial movement thereon and a bar extendingdiametrically across said hole and engaged in said slot to fix saidspider washer against relative turning movement with respect to said"pivot element, and a hut engaged upon the pivot element at the outerside of said spider washer, the inner side of said Washer being inbearing relation with said second blade member.

4. A pivot connection for the blades of scissors or shears, comprisingfirst and second blade members, each having a hole therethrough incoaxial relation one to the other, a cylindrical tubular bearing bushingengaged in said coaxial holes, a bearing washer surrounding said bushingand disposed between said blade members, a pivot element disposed insaid bushing, means fixing said pivot element against relative turningwith respect to said first blade member, said second blade member'beingfree to turn about said pivot element and said pivot element having anexternal thread and being disposed partially within said hole of saidsecond blade member and projecting outwardly therefrom, said pivotelement having a diametrically disposed longitudinally extending slot, aspider washer having a hole loosely engaged about the external thread ofsaid pivot element for free axial movement thereon and a bar extendingdiametrically across said hole and engaged in said slot to fix saidspider washer against relative turning movement with respect to saidpivot element, and a nut engaged upon the pivot element at the outerside of said spider washer, the inner side of said washer being inbearing relation with said second blade member.

References Cited in the file of this patent UNITED STATES PATENTS462,752 Weber Nov. 10, 1891 642,029 Wilkinson Jan. .23, 1900 725,718Johns et a1. Apr. 21, 1903 780,526 Reitz Ian. 24, 1905 1,091,177 WinbergMar. 24, 1914 1,778,346 Zeidler Oct. 14, 1930 2,270,010 Rankin Jan. 13,1942 2,284,664 Kissling June 2, 1942 2,511,187 Weidauer June 13, 19502,582,184 Wheeler Ian. 8, -2

